The Tema Institute Department of Water and Environmental Studies

___________________________________________________________

Transformation of an environmental friendly hydraulic oil in soil using gas chromatography

and FTIR as tools for identification of individual organic compounds and functional

groups

By

Owolabi Yusau Lawal

Master of Science Thesis, Environmental Science Programme, 2007

LINKÖPINGS UNIVERSITET

Rapporttyp Report category Licentiatavhandling Examensarbete AB-uppsats C-uppsats D-uppsats Övrig rapport Master’s Thesis

Språk Language Svenska/Swedish Engelska/English ________________

Titel Title

Transformation of an environmental friendly hydraulic oil in soil using gas chromatography and FTIR as tools for identification of individual organic compounds and functional groups

Författare Author Owolabi Yusau Lawal

Sammanfattning Abstract Production and use of hydraulic ester oil is on the increase worldwide. This becomes a substitute to mineral based hydraulic oil and has drawn more concern because of its more friendly environmental effects. Based on the growing use of hydraulic ester oils in automobiles, transformation of fresh and old hydraulic ester oil was studied in a podsol soil (soil 1) and a clayey soil (soil 2). Functional groups present in the oil and effect of soil types on transformation of the oil were also determined. Replicates of the two soils types were contaminated with fresh or old ester based hydraulic fluid. The oils were recovered from the soil by extraction with acetone. The organic phase was evaporated to dryness, and a small drop of the resulting extract was used for Fourier Transformation Infra Red Spectrometer analysis. The remaining extract was dissolved in hexane and analyzed by gas chromatography. Different intermediate compound patterns were observed in the two studied soils during the transformation studies, which went on for 30 days. Aliphatic-, carbonyl-, aromatic- and ether- groups were the main functional groups present in the tested hydraulic ester oils. Presence or absence of these functional groups distinguishes ester oil from mineral oil

ISBN _____________________________________________________ ISRN LIU-Tema/ES-D-07/02-SE _________________________________________________________________ ISSN ________________________________________________________________ Serietitel och serienummer Title of series, numbering Transformation of an environmental friendly hydraulic oil in soil using gas chromatography and FTIR as tools for identification of individual organic compounds and functional groups Supervisor Susanne Jonsson

Nyckelord Keywords: Transformation, Hydraulic ester oil, Functional groups, and Soil type

Datum Institutionen för Tema

Vatten i natur och samhälle www.tema.liu.se

Date: 01-06-2007

URL för elektronisk version http://www.ep.liu.se/index.sv.html

Abstract Production and use of hydraulic ester oil is on the increase worldwide. This becomes a substitute to mineral based hydraulic oil and has drawn more concern because of its more friendly environmental effects. Based on the growing use of hydraulic ester oils in automobiles, transformation of fresh and old hydraulic ester oil was studied in a podsol soil (soil 1) and a clayey soil (soil 2). Functional groups present in the oil and effect of soil types on transformation of the oil were also determined. Replicates of the two soils types were contaminated with fresh or old ester based hydraulic fluid. The oils were recovered from the soil by extraction with acetone. The organic phase was evaporated to dryness, and a small drop of the resulting extract was used for Fourier Transformation Infra Red Spectrometer analysis. The remaining extract was dissolved in hexane and analyzed by gas chromatography. Different intermediate compound patterns were observed in the two studied soils during the transformation studies, which went on for 30 days. Aliphatic-, carbonyl-, aromatic- and ether- groups were the main functional groups present in the tested hydraulic ester oils. Presence or absence of these functional groups distinguishes ester oil from mineral oil. Key words: transformation, hydraulic ester oil, functional groups, and soil type

2

Table of contents

ABSTRACT..................................................................................................................1

TABLE OF CONTENTS ............................................................................................2

FIGURES......................................................................................................................4

TABLES........................................................................................................................4

ACKNOWLEDGEMENT...........................................................................................5

CHAPTER ONE ..........................................................................................................6

1.1 INTRODUCTION..................................................................................................6

1.2 BACKGROUND ....................................................................................................6

1.2.1 ENERGY CONSUMPTION .......................................................................................6 1.2.2 MINERAL OIL AND OTHER ORGANIC CONTAMINANTS ..........................................7 1.2.3 ESTER BASE HYDRAULIC FLUID ...........................................................................7 1.2.4 LUBRICATING OIL: HYDRAULIC FLUID .................................................................8 1.2.5 FRESH AND USED (SPENT) HYDRAULIC FLUID (LUBRICANTS).............................9 1.2.6 RAPESEED OIL - PHYSICAL AND CHEMICAL PROPERTIES ...................................9

1.3 DEGRADATION PROCESS..............................................................................10

1.3.1 FACTORS AFFECTING DEGRADATION OF OIL IN SOIL.........................................11

1.4 STATE OF THE ART.........................................................................................11

1.5 ANALYTICAL METHOD .................................................................................12

1.5.1. FOURIER TRANSFORMATION INFRA RED (FTIR) SPECTROSCOPY.................12 1.5.2 GAS CHROMATOGRAPHY ..................................................................................12

1.6 OBJECTIVES ......................................................................................................13

CHAPTER 2...............................................................................................................14

2. MATERIALS AND METHODS ..........................................................................14

2.1. LOCATIONS...........................................................................................................14

3

2.2 SAMPLING..............................................................................................................14 2.3 DETERMINATION OF PHYSICAL PARAMETERS ......................................................15 2.3.1 CONTENT OF DRY SOLIDS ..................................................................................15 2.3.2 LOSS ON IGNITION ..............................................................................................15 2.4 CONTAMINANT: HYDRAULIC FLUID.......................................................................15 2.5 EXPERIMENTAL LAYOUT........................................................................................16 2.6 ANALYTICAL INSTRUMENTS ..................................................................................17 2.7 ANALYTICAL PROCEDURE ....................................................................................17 2.7.1 EXTRACTION OF THE SOIL ..................................................................................17 2.7.2 FTIR ANALYSIS .................................................................................................17 2.7.3 GC ANALYSIS .....................................................................................................18

3. RESULT AND DISCUSSION ..............................................................................19

3.1 FUNCTIONAL GROUPS PRESENT IN OIL .................................................................19 3.2 TRANSFORMATION OF FUNCTIONAL GROUPS IN THE OIL DURING DEGRADATION20 3.3 DIFFERENCES BETWEEN ESTER AND MINERAL OIL...............................................21 3.4 ORGANIC COMPOUNDS PRESENT IN OIL ...............................................................22 3.4.1 TRANSFORMATION OF FRESH ESTER OILS IN SOIL.............................................23 3.4.2 TRANSFORMATION OF OLD ESTER OIL IN SOIL ...................................................25 3.5 SUMMARY ..............................................................................................................27

CHAPTER 4...............................................................................................................28

4. CONCLUSIONS ....................................................................................................28

4.1 RECOMMENDATION ...............................................................................................28

REFERENCES...........................................................................................................29

APPENDICES............................................................................................................32

APPENDIX 1.PHYSICAL PROPERTIES OF THE SOILS.................................32

APPENDIX 2.CHROMATOGRAMS OF SOIL AND CONTAMINANT...........33

APPENDIX 3. AREAS FROM GC CHROMATOGRAM....................................35

APPENDIX 4. SPECTRUM FROM FTIR ANALYSES .......................................37

APPENDIX 5. ANALYSIS OF OLD OIL FROM BODYCOTE..........................38

4

Figures FIGURE 1: MAP OF SCANDINAVIA, SHOWING THE SAMPLING LOCATIONS IN SOUTHERN SWEDEN........................................................................................................................14 FIGURE 2: SPECTRUM OF FRESH ESTER OIL....................................................................19 FIGURE 3: SPECTRUM OF FRESH ESTER OIL IN SOIL 1 AFTER 15 DAYS OF INCUBATION. .20 FIGURE 4: CHROMATOGRAM OF FRESH ESTER OIL. HEXADECANE WAS ADDED AS INTERNAL STANDARD....................................................................................................22 FIGURE 5: PRESENCE OF GROUP 1 IN FRESH ESTER OIL (SOIL 1 AND 2) CHROMATOGRAMS. .......................................................................................................23 FIGURE 6: PRESENCE OF GROUP 2 IN FRESH HYDRAULIC ESTER OIL (SOIL 1 AND 2) CHROMATOGRAMS. .......................................................................................................24 FIGURE 7: CHROMATOGRAM OF CONTAMINATED SOIL AFTER 30 DAYS OF INCUBATION. THE CONTAMINANT WAS OLD ESTER OIL. HEXADECANE WAS ADDED AS INTERNAL STANDARD. ...................................................................................................................24 FIGURE 8: PRESENCE OF GROUP 1 IN OLD ESTER OIL (SOIL 1 AND 2).............................25 FIGURE 9: PRESENCE OF GROUP 2 IN OLD ESTER OIL (O.O IN SOIL 1 AND 2) .................26 FIGURE 10: CHROMATOGRAM OF SOIL 2. HEXADECANE WAS ADDED AS INTERNAL STANDARD. ...................................................................................................................33 FIGURE 11: CHROMATOGRAM OF OLD ESTER OIL AGED BY UTILIZED AS HYDRAULIC OIL FOR 16000 HOURS. HEXADECANE WAS ADDED AS INTERNAL STANDARD .....................33 FIGURE 12: CHROMATOGRAM OF OLD MINERAL OIL. HEXANE WAS ADDED AS INTERNAL STANDARD. ...................................................................................................................34 FIGURE 13: FTIR SPECTRUM OF FRESH ESTER OIL IN SOIL I AFTER 30 DAYS OF INCUBATION..................................................................................................................37 FIGURE 14: FTIR SPECTRUM OF FRESH MINERAL OIL....................................................37

Tables TABLE 1: PHYSICAL PROPERTIES OF RAPESEED OIL.........................................................9 TABLE 2: CHEMICAL COMPOSITION OF RAPE SEED OIL..................................................10 TABLE 3: PHYSICAL PROPERTIES OF THE SOILS .............................................................15 TABLE 4: FUNCTIONAL GROUPS IN ESTER BASED HYDRAULIC FLUID ACCORDING TO FTIR.............................................................................................................................20 TABLE 5: % WATER COMPOSITION AND LOSS OF IGNITION (ORGANIC MATTER CONTENT) OF THE TWO SOILS .........................................................................................................32 TABLE 6: AREA (MV*MIN) OF GROUP 1 AND 2 IN CHROMATOGRAMS OBTAINED FROM EXTRACTION OF THE TWO SOILS WITHDRAWN FROM THE DEGRADATION STUDY ...........35 TABLE 7: PRESENCE OF GROUP 1 AND 2 IN THE CONTAMINANTS (SOIL 1 AND 2) AT 0, 15 AND 30 DAYS RESPECTIVELY ........................................................................................35

5

Acknowledgement My gratitude goes to my supervisor: Susanne Jonsson for her constructive criticism and technical input during this study. To Per Sandén, am grateful for developing my interest in interdisciplinary research. Lena Lundman, Saka Matemilola, tutors in the Environmental science program, course mates, friends and family, you all will be remembered for your invaluable contributions. Lastly, am grateful to God for His mercy, grace and favor all through this program.

6

Chapter One

1.1 Introduction Vegetable oil among other alternatives like nuclear energy, solar, wind and water has been suggested as alternative source of energy. However, only vegetable oil is hydrocarbon based and renewable. Based on their triglyceride content, they are good alternatives to fossil fuel. Castor oil, rapeseed, palm oil, soybean, groundnut oil, sunflower oil, corn oil and olive oil are suitable vegetable oil crops (Kalligeros et al., 2003 and Martha et al., 2005). Today, owing to superior performance and environmental friendliness, blend(s) of rapeseed oil (ester) and mineral oil is increasingly used around the world as substitute to mineral oil as bio fuel, base component of lubricating oil, hydraulic fluid and grease used in automobiles. Irrespective of the source of the base component of hydraulic fluid or lubricating oil, it is recommended by most automobile producers that hydraulic fluid or oil should be changed once every three months or at an interval of three thousand miles. This is aimed at ensuring optimum performance (prevent wears and tears) of the automobile (Levermore et al., 2001). In carrying out this change, hydraulic fluid or lubricant are let out of the engine via lids. Hence, regardless of the age of the hydraulic fluid: fresh or used (spent), they could be intentionally or accidentally discharged unto the ground. The prevalence of this practice is high in the forest because heavy-duty engines such as trucks and machines that use this oil in their hydraulic system are frequently used there. Spills of hydraulic fluid can contaminate the soil. Some of this contaminant could be found in the topsoil, where aerobic respiration and degradation is common, due to oxygen supply. Others are found in the subsoil, where anaerobic respiration and degradation is common. However, degradation is faster under aerobic condition, which makes it to be of interest in this study.

1.2 Background 1.2.1 Energy consumption Avinash (2007) explained that according to an estimate, the present sources of energy will last for the following years respectively: coal (218 years), oil (41 years) and natural gas (63 years) thus, if the present rate of consumption is maintained. To accommodate this fear, the EU member states agreed to a 2% biofuel addition to gasoline and diesel by 2005, while it is expected to increase to 5.75% by 2010 (Avinash, 2007) The increasing need for energy and other products obtained from mineral oil is as a result of increasing human population over time. World population was 1 billion in 1820, 1.2 billion in 1850, 1.6 billion in 1900, 2.5 billion in 1950, 5.3 billion in 1990 and 6 billion in 2000 (Mc Neill, 2000). Today, it is estimated at about 6.6 billion by the America’s census bureau (U.S Census Bureau in USA). With obvious increase in population and demand for fossil fuel; 10 thousand million metric tonnes of oil was used in year 2000, while only 800 and 250 million metric

7

tonnes were reported for 1900 and 1800 respectively (Smil, 2003), there is need for alternative sources of energy and other products (grease, lubricating oil and hydraulic fluid) obtained from mineral oil (fossil fuel). However, these alternatives should be renewable and cost effective. 1.2.2 Mineral oil and other organic contaminants Mineral oil remains the main source of energy and other hydrocarbon based products. Its dominance was enhanced by high demand for energy.Increasing demand for energy was stressed by Mc Neill (2000):during the twentieth century, world economy increased by a factor of fourteen, industrial output increased by a factor of forty, while energy use increased by a factor of sixteen . In 1996, the world resource institute gave the world energy mix as 3% hydropower, 27% coal, 23% natural gas and 40% natural oil. This shows more dependence on mineral based oil (Smil, 2003). The increasing use of mineral oil is indicative of increasing production of other products like lubricating oil, grease and fluids. Pollution resulting from increasing use of mineral based oil could not be over-emphasised. Large quantity of mineral based oil finds there way to the ground. Some are transported through water bodies and sewers, where they eventually sink into sediments (US EPA, 1994). In United States, it is estimated that 1.4 billion gallons of used oil are produced yearly.200 million gallons of this estimate find their way to the ground: discarded in household waste or poured into sewers and large water bodies (US EPA, 1994). Several million of tons of oil cause pollution world wide yearly. Different classes and composition of compounds occur in used oils. Aliphatic hydrocarbons account for 73–80% of the total constituent. Present in this class are alkanes and cycloalkanes of 1-6 rings, diaromatics and monoaromatics account for 2-5% and 11-15% respectively (Vazouez-Duhalt, 1989) Organic compounds occurring in the environment include naturally produced straight, branched or cyclic aliphatic hydrocarbons, aromatic hydrocarbons and oxygenated hydrocarbons such as esters, ketones, ethers, alcohol and aldehydes (Pal and Singhal, 2006). These compounds could be volatile, semi-volatile or non-volatile organic compounds with boiling points of <0o to 50-100oC, 50-100oC to 260oC and 380-400oC, respectively (Pal and Singhal, 2006). However, organic compounds in our nature are also of anthropogenic origin, such as pesticides, herbicides, cleansing materials, industrial discharge or waster, consumer products, tobacco smoking and gas flaring and other combustion sources. 1.2.3 Ester base hydraulic fluid The possibility of the world running short of mineral oil, high price (economic implication), health implications and environmental impact, necessitates the need for alternatives to mineral oil. Vegetable oils like rapeseed oil are known to contain triglyceride. These triglycerides are affordable, renewable and environmentally friendly (Ensinar et al., 2002). Other sources of vegetable oils, which are of importance, are castor oil, palm oil, soybean groundnut oil, sunflower oil, corn oil, and olive oil (Kalligeros et al., 2003)

8

Rape plant takes in more carbon dioxide from the atmosphere for metabolic activities than what they release during combustion. Oil from rape plant is easily transported and stored. Rape oil also has almost the same heating value as diesel oil and releases almost no sulphur (Ensinar et al., 2002). 1.2.4 Lubricating oil: Hydraulic fluid Lubricating oil exists in different states: liquid, solid and semi solid. Lubricating oils are produced in different formulations for different purposes. The composition is mainly of two fractions: base fluid and chemical additives. According to Zie (1997) the major component of lubricant materials is hyrocarbon (base fluid). Chemical additives account for about 5–20%. They are included for specific functions (Jirasripongpun, 2002) dispersants, anti-oxidants,detergents, anti-wear agents, corrosion inhibitors and viscosity index improvers (Zie, 1997) While in use, some of the additives are broken down and the resulting products are characteristic of the specific oil. Therefore degradation of additives and differentiation of oil samples at various degrees of their use can be observed and studied to ascribe particular characteristics to a particular lubricant (Zie, 1997). Hydraulic fluid is a form of lubricant existing in the liquid state. It is the most widely used form of lubricant in automobiles and other machines (Pal and Singhal, 2006). Hydraulic fluid as a lubricant can be vegetable derived or mineral derived (Mercurio et al 2003). Though both consist mainly of hydrocarbons, the latter has been in use longer than the former. However, blend of the two sources are now common due to their superior performance and environmental friendliness. Mineral based hydraulic fluid is produced from refining process aimed at extracting a wide range of fuels and lubricating oils with respect to their individual boiling points and viscosity. Vegetable based hydraulic fluid is produced via chemical addition of a methyl group to fatty acid, which yields ester based oil. Different types of lubricating oils are produced from refining process and transesterification processes. These include industrial transmission oils, hydraulic oils, heat-transfer oils, cutting oils, electrical oils and engine oils (Pal and Singhal, 2006). According to Pirri and Wessol (1998), the primary role of hydraulic fluid is to reduce mechanical wear. However, the capability of extreme pressure type fluid to prevent scuffing, scoring and seizure as quantity of applied load increases is also closely related to wear reduction. The friendliness of a hydraulic fluid is based on its suitability to the environment. This is determined by the following factors: biodegradability, toxicity, bioaccumulation and biomagnification, and proportion of renewable raw material. Though there are some concerns about cost effectiveness of producing ester based hydraulic fluid and fuel as a replacement for mineral based oil, advantages such as high lubricity, low lubricant consumption, viscosity-temperature relationship, energy efficiency, public health, safety and environmental friendliness has offset the initial cost implication (Anand and Chhibber, 2006).

9

Today, emphases are on blends of mineral and ester based hydraulic fluids because of the problems associated with use of pure vegetable based lubricants in machines (Petro-Canada, 2007) 1.2.5 Fresh and used (spent) hydraulic fluid (lubricants) Ageing of hydraulic fluid is determined by the duration over which it has been used or distance covered by the equipment using it. Fresh lubricants (hydraulic fluid) are light in colour, while used or spent lubricants are dark in appearance. Fresh hydraulic fluid is aged/transformed via chemical processes such as nitration and oxidation (Remmele and Widmann, 2006), upon which they become old. The main process these fluids undergo is oxidation. According to Vazouez-Duhalt (1989), mineral based used lubricant contains small quantity of additives, gasoline, nitrogen and sulphur compounds, and metals such as calcium, barium, lead and magnesium and aromatic and aliphatic hydrocarbons with chain lengths ranging from C15 – C50. Used lubricant contained more proportion of polycyclic hydrocarbons and lesser quantity of additives as compared to fresh lubricant (Hewstone, 1994). 1.2.6 Rapeseed oil - physical and chemical properties Rapeseed or canola oil is cultivated in most polar countries such as Sweden, Canada, United Kingdom and Iceland. It is an oily plant and was originally a weed until it was improved genetically, thus becoming useful oil for industrial, human and animal consumption (Alonso et al., 2006). Rape oil can be used as bio-fuel, hydraulic fluid, surface coating, grease, lubricant, medicine and polymer. Rape oil is favoured as a base constituent of hydraulic fluid because of its high viscosity index, low friction coefficient, ability to endure mechanical stress, high polarity and ability to adhere to metal surface (Merrain, 1989). Other physical properties of rapeseed oil are listed in Table 1. Sagar (1995) mentioned that apart from rapeseed oil being renewable, the carbon released during combustion of the plant is taken up during photosynthesis. Thence it is used for production of fatty acid in the plant. This process reduces global warming by decreasing carbon content in the atmosphere. According to Dagaut et al., (2007) rapeseed oil methyl ester is a mixture of C14-C22 esters. The oxygen content in the fatty acid is about 10.8%. This aid combustion and reduces emission of harmful substances. They have almost zero sulphur content (0.04 – 0.002%). Other chemical properties of rapeseed oil are listed in Table 2.

Table 1: Physical properties of rapeseed oil Properties Rape Density at 15 C (Kg/m3) Density at 35 C (Kg/m3) % S in mass % C in mass % H in mass % O in mass

921 909 0.03 79.6 11.4 8.97

Source: KOIPE S.A factory Andujar (Jaen) cited by Alonso et al., (2005)

10

Table 2: Chemical composition of rape seed oil Fatty acid Refined rape oil (%) Raw rape oil (%) C < 14 Myristic C 14:0 Palmitic C 16:0 Palmioleic C 16:1 Estearic C 18:0 Oleic C 18:1 Linoleic C 18:2 Linolenic C18:3 C ≥ 20 Iodine index Sapronification index Saturated/unsaturated

- 0.06 4.72 0.24 3.01 54.62 27.2 7.14 3.01 98 172 0.1

- 0.05 4.32 0.23 2.77 60.27 19.58 9.19 3.59

Source: KOIPE S.A factory Andujar (Jaen) cited by Alonso et al., (2005) Four main criteria were mentioned to be of importance when classifying or evaluating oils. These are: uses, price, intrinsic chemical properties (degree of impurities, humidity, impossible to saponify, fatty acid polymers, strange or toxic substances) and, energy potential and composition: percentage of triglycerides and energy content (Remmele and Widmann, 2006)

1.3 Degradation process Degradation is the gradual breakdown of organic matter into other products. Degradation involves transformation of organic substances into other organic products whose end formation is water and carbon dioxide during aerobic conditions and methane during anaerobic conditions. Degradation could be induced chemically, biologically by microbes or physically by light (Norton, 2002). Biodegradation refers to degradation caused by biological agent such as microbes existing naturally in the soil. In nature, microbial degradation of synthetic pollutants occurs without man’s cognisance of the biochemical processes taking place within the microbial community (Silke et al., 2001). Hence, biodegradation is an important process because it naturally brings about remediation of hydrocarbon or other contaminants in the soil (Norris, 1994). Degradation of soluble organic material by microbes in the vadose (water unsaturated) zone is very important to prevent ground water contamination, where degradable materials may pollute the aquifer by creating anaerobic condition, building up fermented products and high concentration of manganese and iron (Lovley and Anderson, 2000; Hansen et al., 2001) Since it is practically impossible to determine the end point of a degradation process, the quantity of contaminant remaining in the soil after the remediation process is used as an indicator. Also, bioassays are used as alternatives because it takes into account bioavailability of contaminant and intermediate or final products that may emerge from the transformation of the original contaminant (Van Gestel et al., 2001).

11

Degradability of contaminants such as hydraulic fluids depends on the chemical composition of the oil. As such, vegetable (ester) derived hydraulic fluid to some extent is similar to mineral based as well as the blend, because they all possess almost the same chemical constituent in their base fluid determines (Silke et al., 2001). 1.3.1 Factors affecting degradation of oil in soil The presence of oil in an ecosystem is affected by a number of factors (abiotic and biotic influences). These factors account for the transformation or loss of some of the components leading to intermediate products or other end products (Yukiko et al., 2003). Atlas (1981) mentioned the following as some of the factors affecting metabolization of hydrocarbons in the soil: microorganisms present in the soil, oxygen, nutrients, pH-value, temperature, water content, soil type, quality and quantity of the contaminant present. Also of importance is the pollution history of the soil and the rate at which the composition of the contaminant changes. Hydrocarbon-degrading microorganisms are unevenly distributed in land, soil and aquatic environments. Population wise, they account for less than 1% of the total microbial communities present. However, their population increases during pollution caused by hydrocarbon to about 10% of the community.

1.4 State of the art Though studies on degradation of blends of ester based hydraulic fluid such as those made from rapeseed and mineral oil is pristine. However, some studies in on other ester-based and mineral based lubricants have been carried out. According to Haigh (1994), studies has shown that ester based lubricants are more biodegradable than conventional mineral based oil in aquatic environment. Optimum conditions have been attached to laboratory investigation over time; hence results obtained from the laboratory may not directly indicate happenings in the field. To bridge the gap existing between field and laboratory situation, Morelli et al., (2005) investigated the biodegradation and effect of synthetic lubricants in field plots. The result shows that synthetic lubricants degrade more rapidly than mineral oil based lubricant. However, natural vegetable oil was found to degrade faster than both synthetic lubricant and mineral based hydraulic oil. The extent and rate at which the oil degrades in the field plot was found to be much lower than previously reported for laboratory studies. According to Philip et al., (1974) biodegradability of vegetable and mineral derived lubricant were tested in tropical soils. The result shows that after 14 days, vegetable derived lubricant degraded significantly (12%) when compared to mineral derived lubricant in the presence of mangrove or coral reef microbial community.However, mangrove-source microbial community degraded the lubricants better than that of the coral reef. Jirasripongpun (2002) reported that oil-degrading microorganisms were isolated from cultures of scale soil. 16S rDNA gene was used to identify the isolate while degradability of fresh and spent lubricating oil was determined. The weight of the extracted remaining oil shows that most of the isolates degraded fresh lubricating oil more than spent oil.

12

Zhang et al., (2007) studied the toxicological effect of lubricating oil on germination, early growth and physiological responses of a mangrove plant in Hong Kong called Bruguiera gymnorrhiza. The result showed that fresh and spent lubricating oil exposed to an initial dose of 5 lm−2 did not have any effect on germination as well as all the propagules development. The control as well as the oil-treated propagules successfully germinated into new seedlings within 30 days. However, germination of Aegiceras corniculatum, Blanco and Acanthus ilicifolius in sandy and muddy mangrove sediments was totally inhibited by fresh and spent lubricating oil at the same dose. These results indicate that lubricating oil (spent) and fresh could pose serious threat to plant growth at high concentrations. Shane et al., (2007) investigated biodegradation of hydrocarbon in clean sediment obtained from O’Brien Bay and Sparkes Bays, East Antarctica, which were contaminated with a mixture of lubricating oil and special Antarctic Blend diesel fuel. The contaminants were introduced into a contaminated bay (Brown Bay) to evaluate the influence of past contamination on biodegradation process. After 11 weeks, the result shows different patterns of degradation in each bay. Brown bay had the most extensive degradation index out of the three bays. This implies that degradation of the contaminants occurred in the sites, but previous history of contamination promote rapid degradation.

1.5 Analytical Method 1.5.1. Fourier Transformation Infra Red (FTIR) Spectroscopy According to studies by Didem and Filiz (2004), Fourier Transformation Infra Red (FTIR) spectroscopy can be used to determine the functional groups present in bio-oil made from rapeseed. The method of operation involved in FTIR is called interferometric infrared spectroscopy. The results from FTIR are displayed as spectrum showing peaks of specific wavelengths and synonymous with a particular functional group. FT-IR has some advantages over other infrared spectrometer. This includes: no slit, hence all the energy produced by the source is utilized and the collection of the spectroscopic data is done simultaneously (William 1991). Infrared spectra are suitable for identifying chemical compounds because every molecule except diatoms such as chlorine (Cl2) nitrogen (N2) and oxygen (O2) has an infrared spectrum. The vibration frequencies of compounds depend on the masses of the constituent atoms and the strengths and geometry of the chemical bonds. However, the spectrum of every molecule is unique except for optical isomers. Identification of unknown compounds is possible by comparing their spectra with known spectra (William, 1991). 1.5.2 Gas Chromatography Gas chromatography (GC) is commonly used as a standard means of detecting and quantifying complex mixtures of volatile organic and inorganic compounds (Douglas and Donald, 1982, Environmental protection Agency, 2005). It can also be used for quantitative analyses of bio-oil (Didem and Filiz, 2004). Since the GC has the ability

13

to fractionate the components of a vaporized sample based on the partition between the gaseous phase (mobile) and the stationary phase in the column cum its detectors being able detect the quantity of solutes emitted from the column (Douglas and Donald, 1982).

1.6 Objectives The literature review shows extensive studies on degradation of products, which are mineral based because of the importance attached to it over the years.Since mineral based lubricant has being the favorite in the past, while today’s focus is on environmental friendly lubricants, it is important to investigate transformation of a supposed environmentally friendly hydraulic fluid of different ages in the soils, determine the functional groups present in the fluids and know if soil type affect degradation rate of the fluid Poised by frequent happenings in the forest, environmental friendly hydraulic fluid becomes a contaminant in the soil. Therefore, its presence in forest soil becomes of great environmental concern. Based on the environmental implication, it will be of interest in this research to investigate the following under aerobic condition:

• What happens to fresh and used environmentally friendly hydraulic ester oil in the soil?

• Does soil type affect the transformation of used and fresh hydraulic ester oil? • What functional group(s) is/are present in hydraulic ester oil?

14

Chapter 2

2. Materials and Methods 2.1. Locations This research was carried out at department of Water and Environmental Studies, within the master program at TEMA, Linkoping University, Sweden under the supervision of Susanne Jonsson (Ph.D). 2.2 Sampling Of interest in this research is the vadose zone of the soil, i.e region above the water table but below the soil surface. Degradation is faster at this zone in the soil: due to high population of microorganism and air.Thus, a depth of 1-15cm below the soil surface is preferred due to its aerobic nature Soil samples were collected in February, 2007 from two locations in Sweden: a well developed coniferous forest with a typical podsol soil at the county called Betlehem northeast of Norrkoping (soil I) and a deciduous forest at Valla with a more claylike soil (soil II) close to campus Linköping in Linköping. The exact positions of soil I and II are N58°44'0.86", E16°20'15.70" and N58°24'2.47", E15°35'36.40",respectively (Figure 1). Plant covers at the sampling sites were removed to give a clear view of the sampling site. 3 kg of soil was sampled within 1-15 cm depth of the soil profile at both locations. The organic matter content of forest Betlehem (soil 1) occupied 0-5 cm of the soil profile, while the greyish brown region was about 6-15cm below the surface. The soil profile in forest Valla (soil 2) showed 0-2 cm organic matter (dark region), while the later part 3-12cm (greyish brown region) showed portion of ion exchange.

Figure 1: Map of Scandinavia, showing the sampling locations in Southern Sweden Source:www.lib.utexas.edu/maps/europe/sweden_div96.jpg

Soil 2: N58°24'2.47", E15°35'36.40"

Soil 1:N58°44'0.86", E16°20'15.70

15

Soil samples from each location were collected in clean transparent plastic sampling bags. They were mixed in the laboratory separately and sieved through a 2 mm diameter metal sieve to remove stones, roots and other unwanted materials.This process ensured homogenous mixture. 2.3 Determination of Physical parameters

2.3.1 Content of dry solids The dry solid content was determined according to standard method SS-ISO 11465 by weighing a known quantity of wet soil sample into a crucible of known weight and drying the soil in an oven at 105oC for 24hrs. The weight of the dry soil after oven drying was determined by subtracting the weight of the crucible from the weight of the crucible and the dry soil. Percentage water composition was an expression in percentage of the difference between weight of wet soil sample and weight of dry soil to the wet soil sample. (see Appendix I for details) Fraction dry solid = 1-(wt. of wet soil – wt. of dry soil) wt. of wet soil

2.3.2 Loss on ignition The fraction of organic matter in the soils was determined as loss on ignition according to standratd method SS-ISO 12879 . This was done by placing the dry soil in a furnace (NABER-Industrieofenbau 2804 Lilienthal Bremen) for four hours at 550oC. This process removes (mainly) the organic matter content of the soil by combustion. (See Appendix I for details) The soil was then allowed to cool in a desicator and weighed. Organic matter content is an expression in percentage of the difference between the weight of dry soil and burned soil to the dry soil. See Table 3. % loss on ignition = wt. of dry soil – wt. of burnt soil * 100% wt. of dry soil 2.4 Contaminant: Hydraulic fluid Fresh and used hydraulic fluids were kindly provided by Maskinia AB, Linköping. The contaminant used in this study was a commercial mixture of mineral and vegetable based hydraulic fluid. The brand name was ENVIRON MV 46 (Panolin HPL synthetic 46) hydraulic fluid, produced by a company called Petro Canada located in Canada.

Though there exist a wide range of products used by automobiles from this company, ENVIRON MV 46 was designed for both mobile and stationary heavy-duty automobiles operating at extreme temperatures.

Table 3: Physical properties of the soils

Soil type Soil I (podsol) Soil II (clayey soil) % water composition 49.471 71.056 % organic matter content 35.229 18.903

16

The base fluid was about 99.9% pure, which offered it a superior quality. The source of the vegetable component of the base fluid was esterified rape oil. Percentage composition of mineral base, ester base and additives were 40-60 %, 40-60% and 10% respectively (Petro-Canada, 2007). In this study, the age of the fresh hydraulic fluid was 0 hours, while that of the used hydraulic fluid was 16000 hours. According to Petro-Canada (2007) the superior technology available to the company ensures the following special features, which ensures environmental friendliness of the hydraulic fluid:

• Non-toxic and very low odor: thus it is non-toxic to water-inhabiting species, non carcinogenic and contributes to a cleaner, safer and more pleasant work environment. In terms of degradability, more than 30% of the fluid is expected to degrade within 30 days, while it can be recycled and reclaimed unlike pure vegetable based products which have to be incinerated or land farmed.

• Its superior tribological and chemical properties include: ability to meet and

surpass performance requirements of conventional anti-wear hydraulic oils, long oil life, which extends the time between oil change. It also minimizes sludge and varnish deposits to ensure smooth and reliable operation of hydraulic valves and actuators. The fluid allows systems to start at temperatures as low as –34oC and provides excellent lubrication of hydraulic component at high operating temperatures. Unlike vegetable oils, it does not get over time at moderately low temperature.

The ester based hydraulic fluids were compared chemically with fresh and old mineral based hydraulic fluids called Petro Canada ECO HT-E, which also was provided by Maskinia AB, Linköping. The mineral based oils were of the same age as ester based oils. 2.5 Experimental layout The ester based hydraulic fluids (fresh and old) and mineral based hydraulic fluids (fresh and old) were analyzed using FTIR spectrometer (1725) and gas chromatograph (HP 6890). Soil I and II were also analyzed with the same techniques after extraction with acetone. In order to make a time series for degradation study, the two soils were divided into four groups (each group contained soils of equal quantity and were sampled at different time). Each group consisted of sixteen bottles, inclusive the control setup. The last group was designed for future studies. Control: three replicates of the control setup were prepared for each group. This consisted of only soil I and soil II (15g) in separate 100ml soda washed bottles i.e no contamination of hydraulic fluid.The control set up was analysed during the first and last sampling. Three replicates of the two soils (15g each) containing were contaminated with 2.0 ml fresh or old ester based hydraulic fluid using an automatic pipette. All setups

17

commenced the same day. This was necessary to ensure clear bases for comparing transformation pattern as degradation of the hydraulic fluids in the two soils occur. Sampling was done on 0 day, day 15 and day 30. It should be mentioned that water was sprinkled unto the samples at 5 days interval to ensure as stable moisture content as possible. The quantity of water added was determined visually by the appearance of the soil in the bottles. The bottles were not covered to ensure adequate supply of air to the bottles (aerobic degradation). They were kept in darkness and incubated at room temperature of 20oC. 2.6 Analytical Instruments A FTIR instrument (Perkin Elmer 1725) was used to determine the functional groups present in both esters based, and for comparison, mineral based hydraulic fluid. A gas chromatograph (Hewlett Packard (HP) model 6890) equipped with a flame ionisation detector (FID), which is a general detector detecting reduced carbon containing compounds was used to quantify the constituent of semivolatile organic compounds present in the contaminant extracted from the soils. 2.7 Analytical Procedure

2.7.1 Extraction of the soil During sampling, 20.0 ml of acetone was added to the sample for extraction of the oil. The bottles were then covered, though loosely tightened, and placed in an ultrasonic bath (Bandelin Sonorex RK 510H) at room temperature for 10 minutes.Placing the bottles in a rotating chamber for one hour at 100 rpm to continue the extraction process immediately followed the ultrasonic process.These processes ensured maximum recovery of the oil.After the shaking process, the overlying solution in each bottle was removed using a pipette into a centrifuge tube.The tubes were covered and placed in an induction drive centrifuge (Beckman Model J2-21m) operating at 2500 rpm for 15 minutes at 25oC. The centrifugation resulted in clear solution void of particles; the particles settled as sediments down in the tube.After the extraction process, 2.0 ml of the organic solution was introduced into 4 ml disposable glassware and was evaporated to dryness by a gentle steam of nitrogen.

2.7.2 FTIR Analysis Prior analysis, nitrogen gas was flushed through the detection chamber of the FTIR to purge any CO2 or water vapor present in the instrument. This was necessary to minimize interferences, which would otherwise reduce the enhance production of good quality spectra. Potassium bromide (KBr) was pressurized and made into thin plates (2-3 mm thick) and a drop of the sample (concentrated form) was dropped on the plate. It was ensured that the sample was evenly distributed on the KBr plate before placing it in the beam. The sample absorbs specific IR frequencies and their intensities are reduced in the interferogram. The infrared absorption spectrum produced for each scanned sample is the Fourier transformation. The designated range of wavelength (λ) used for this study was 400 – 4000 nm, the percentage intensity was from 0 -100%, absorption was 0 – 10 and the number of scan was one.

18

Prior to scanning of the samples, the background of the instrument and the KBr plate were scanned in order to identify the spectrum originating from the samples. To ensure perfect KBr plates, the salt was dried in an oven at 105oC for 3 hours to eliminate water content and stored away from light source. A small drop of the concentrated extract (containing mainly the contaminant) was introduced onto potassium bromide (KBr) plates used for FTIR analyses.

2.7.3 GC analysis In this study, the retention time and number of ions produced from the analyte was measured by GC-FID.The oven temperature program was as follows: 40oC for 5 mins increasing at 30oC/min to 80oC, then increased at 5oC/min to 180oC and finally at 10oC/min to 270oC for 5 mins. The GC made use of a front injector with a split ratio of 1:50. The injector temperature was 280oC, while the detector temperature was 250oC. The carrier gas through the column was helium and the flow rate was 1.2 ml/min. The column was 29.0m long with an inner diameter of 0.5mm, while the film thickness was 0.25 μm. The remaining extract from that used for FTIR analysis was dissolved in 2.0 ml hexane._10μl solution containing 40ng/l hexane of n-hexadecane (C16H34) was introduced as internal standard. The resulting solution was then covered and shaken to give a homogenous solution, of which 1 μl was injected in the gas chromatograph (GC) for analysis. Prior and after injection of the sample into the gas chromatograph, the injection needle was washed with acetone and hexane to wash out residuals.

19

Chapter 3

3. Result and Discussion Visual inspection of fresh and old hydraulic ester oil used in this study revealed that old hydraulic ester oil is dark, while fresh hydraulic ester oil is slightly yellowish in color. The difference in color between the fresh and old hydraulic ester oil might be due to the interaction between the old oil and the automobile parts, while in use. This interaction results in chemical processes such as oxidation or nitration and addition of metals (which may account for color change of the oil). This finding agrees with the findings of Remmele and Widman (2006) who reported that fresh hydraulic fluid is transformed via chemical processes such as nitration and oxidation, upon which they become old. 3.1 Functional groups present in oil FTIR was used to give qualitative analysis of the contaminants in the soils. To this effect, the functional groups present in the contaminant were determined by comparing the peaks in the spectrum at specific wavelengths. Only selected representatives of each sampling are presented because other spectrums from samples within the same group were similar in appearance. The functional groups present in the ester based hydraulic fluid are explained as follows: The vibration caused by C-H stretching could be found at wavelengths above 3000cm-

1 (Figure 2, Table 4). This indicates the presence of aliphatic hydrocarbons. Between 1600 and 1800 cm-1 another distinctive peak could be noticed. This is C=O, i.e. carbonyl group, which could account for the carboxylic acid and/or ester structure as well as ketones present in the organic structure of the hydraulic oil. A peak caused by an aromatic structure could be seen at 1450–1600cm-1. Lastly, C-O (ether) groups and aromatic rings can be seen between 1000 and 1100 cm-1. These results are in agreement with findings by Didem and Filiz (2004).

Figure 2: Spectrum of fresh ester oil.

20

Table 4: Functional groups in ester based hydraulic fluid according to FTIR

3.2 Transformation of functional groups in the oil during degradation Some peaks, which were not conspicuous after 15 days of incubation, were prominent after 30 days (Figures 3 and 13). Apart from the peaks earlier reported, some peaks could be noticed between the following wave lengths: 1100–1200cm-1 and 1300–1400cm-1. The appearance of these peaks over time could be due to accumulation of compound(s) having a particular functional group during the incubation period, not specified in Table 4, during the incubation period.

Figure 3: Spectrum of fresh ester oil in soil 1 after 15 days of incubation.

Functional groups Wavelength (cm-1-) C-H (aliphatic) 3000 C=O (carbonyl) 1600 - 1800 C=C (double bonds) 1450 - 1600 C-O (ether) 1000 - 1100

21

The individual peaks in the FTIR spectrum of old hydraulic ester oil were more pronounced than the individual peaks in the FTIR spectrum of fresh hydraulic ester oil (Figure 13 and 2).The presence of more individual peaks in the chromatogram of old ester oil (Figure 11) may be due to degradation of methyl ester as temperature increases in automobiles while at work. This leads to formation of fatty acids (carboxylic acids) and methanol (alcohol). Thus, the presence of carbonyl group (C=O), which account for carboxylic acid was noticed between 1600 and 1800 cm-1 in the FTIR spectrum of both fresh and old hydraulic ester oil. However, the quantity of carboxylic acid in old hydraulic ester oil is more than that in fresh hydraulic ester oil because the old oil was more hydrolyzed than fresh oil due to degradation process, while in the hydraulic system of automobiles. Water residue present in the extract used for FTIR analysis account for the peak noticed at 3500 cm-1 in the spectrum. This finding is buttressed by the results of the soap analysis of the old hydraulic ester oil used in this study by Bodycote Testing Company (an accredited fuel and lubricant testing and chemical analysis company). The acid number, which denotes presence of carboxylic acid, was found relatively high. Water content and elements such as zinc, iron, copper, aluminum, chromium and silicon were also of high quantity (Appendix 5) 3.3 Differences between ester and mineral oil Based on qualitative analysis, both the ester and mineral oils seem similar. The similarity may be because they are both hydrocarbon based. However, peaks at wavelengths between 1000 and 1600 cm-1 appear to be more pronounced in fresh ester oil (Table 4, Appendix 4, Figures 2 and 14). Differences exist when comparing ester and mineral oil because of the type of functional groups and additives present as well as the production process they undergo. To give a qualitative interpretation, visual appraisal of Appendix 2, Figure 11: chromatogram of old ester oil aged by utilized as hydraulic oil for 16000 hours, and Figure 12: chromatogram of old mineral oil were considered. It was observed that peak group 1 and 2 (explanation is given below) were conspicuous at retention time of 16.189 and 37.612 respectively in the chromatogram of old ester oil. These peak groups were not that conspicous in the chromatogram of old mineral oil. Another peak group which distinguishes old mineral oil from old ester oil was noticed between retention time of 20.4 and 30.1 min in chromatogram of old mineral oil. The presence and/or absence of these peaks in ester and mineral based oils were most probably due to the difference in their base constituents, rate of oxidation and other chemical processes these oils undergo in automobiles. Vazquez (1989) reported that heating and oxidation processes are the main changes these hydraulic fluids undergo. The percentage composition of the base constituents and chemical additives of these oils differentiates one oil type from the other (Jirasripongpun, 2002) Though the end point of degradation of hydraulic fluid or oil (contaminant) cannot be easily determined, the quantity of the contaminant remaining in the soil after degradation is used as an indicator (Van Gestel et al., 2001). However, transformation of the contaminant forms intermediate products during the degradation process. They could exist in different forms.

22

3.4 Organic compounds present in oil In this study, individual organic compounds in a chromatogram are mentioned as a peak and peak group means clusters of organic compounds that resemble each other in volatility and chemical properties. Figure 4 shows a chromatogram of fresh ester oil (sample) while Appendix 2 (Figure 10) shows the content of organic compounds in soil 2. This is a representative chromatogram of the two soils used in this study. With the absence of any peak in the chromatogram, the soil contains neither contaminant prior to inoculation nor any natural organic compounds, which could interfere with peaks originating from the contaminant. These two give clear bases for comparison at different stages of incubation. For the purpose of this study, two important peak groups (1 and 2) were selected from the chromatograms as representatives to explain the transformation of the contaminant in the soil. These two peak groups were selected because they represent a major part of the integrated area in the chromatograms. These groups are probably the C14-C22 methyl esters and the corresponding fatty acids. The methyl esters elute faster than the fatty acids and therefore have shorter retention time. Each group denotes a group of compounds or mixtures that would probably change during the degradation process. The change could either be quantitatively or qualitatively.Here, the focus is more on quantitative changes.

-100

200

400

600

900

4,0 10,0 15,0 20,0 25,0 30,0 35,0 40,0 45,0

mV

min

April 2007 #21 fresh est oil Int_Chan_2

1 - Group 1 - 16,613

2 - Hexadecane - 20,284

3 - Peak 1 - 29,912

4 - peak 2 - 31,121

5 - Group 2 - 38,2

Figure 4: Chromatogram of fresh ester oil. Hexadecane was added as internal standard

23

3.4.1 Transformation of fresh ester oils in soil

Almost the same quantity of group 1 in fresh hydraulic ester oil was found in both soils during the first sampling (0 day).This was because the same quantity of contaminant was introduced in both soils at about the same time. Following inoculation of the soils with contaminants, the microorganisms present in the soil need to adjust to the presence of the contaminants: there was no contaminant in the soil before inoculation. Appendix 2, Figure 10 shows the chromatogram obtained after extraction of the soil prior to inoculation. There was an increase in compounds amounting to group 1 in both soils at 15 and 30 days as compared to 0 day. However, more of these compounds were found in soil 1 at both occasions. The increase of group 1 in both soils after 15 and 30 days respectively may be due to difference in soil type and microbial population in the soils. The result of T test performed to compare group 1, F.O in soil 1 and 2 after 0 and 30 days of incubation gave 0.063 and 0.070 respectively. These values were higher than 0.05, which was set as the level of significance. Therefore, statistics proves that there was a significant increase in compounds forming Group 1 in both soils. This finding agrees with Atlas (1981). Same pattern of increase in the formation of Group 1 over the sampling period could be noticed in both soils. Presence of compounds gathered in group 2 is shown in Figure 6. The graph shows that soil 2 had more of group 2 at 0 day, when compared to soil 1. However, reverse was the case for 15 days in the two soils, while both soils showed almost same quantity of group 2 at 30 days. The high values noticed in the graph were due to analytical error resulting from change of injector type from split to splitless.

Figure 5: Presence of group 1 in fresh ester oil (soil 1 and 2) chromatograms.

24

Figure 6: Presence of group 2 in fresh hydraulic ester oil (soil 1 and 2) chromatograms. This pattern is different from what was reported for that of group 1 observed in fresh ester oil (both soil 1 and 2) described above. This difference in pattern, which resulted in higher quantity of group 2, F.O could be caused by difference in transformation of the contaminant and soil type. Findings by Atlas (1981) agree with this report. The result of T-test performed to compare group 2, F.O in soil 1 and 2 after 0 and 30 days of incubation gave 0.025 and 0.028 respectively. These values were lower than 0.05, which was set as the level of significance. Therefore, statistics proves that there was no significant increase in compounds forming group 2, F.O in both soils.

Figure 7: Chromatogram of contaminated soil after 30 days of incubation. The contaminant was old ester oil. Hexadecane was added as internal standard.

-100

0

100

200

300

400

500

600

4,0 10,0 15,0 20,0 25,0 30,0 35,0 40,0 45,0

mV

min

April 2007 #10 3 soil 1+ old 3 Int_Chan_2

1 - Group 1 - 16,641

2 - Hexadecane - 20,249

3 - peak 2 - 31,093

4 - Group 2 - 37,655

25

3.4.2 Transformation of old ester oil in soil Based on usage time, the old ester oil used as contaminant in this study was used for 16000 hours by heavy-duty vehicle. Figure 7 shows the chromatogram of old ester oil. By visual appearance, peak group 1 and 2 appeared in both chromatograms showing old ester oil (O.O; Figure 11) and at the same retention time range as the fresh ester oil (Figure 4); this could be because both contaminants contained the same base components. However, old ester oil had undergone chemical processes such as oxidation in the hydraulic system; this most probably resulted in changes in chemical composition of the oil, with the formation of more intermediate products. Peak group 1. There was an increase in the quantity of group 1 found in both soils over the incubation periods (Figure: 8) with old ester oil. However, the quantity of group 1 found in soil 2 at 0 day was more than what was found in soil 1. The difference is within the analytical error. 15 days and 30 days of incubation showed the same pattern for group 1 in old oil, which was different from 0 day. This conforms to the initial report on pattern of transformation of group 1 in fresh ester oil in both soils. The result of a T-test performed to compare group 1, O.O in soil 1 and 2 after 0 and 30 days of incubation gave 0.071 and 0.085, respectively. These values were higher than 0.05, which was set as the level of significance. Therefore, statistics proves that there was a significant increase in compounds forming group 1, O.O in both soils.

Figure 8: Presence of Group 1 in old ester oil (soil 1 and 2)

26

Figure 9: Presence of group 2 in old ester oil (O.O in soil 1 and 2) Peak group 2. Presence of group 2 in both soils contaminated with old oil is shown in Figure 9. The graph shows that more quantity of group 2 was observed from the third sampling as compared to the first sampling in both soils. However, the quantity in soil 2 was more than soil 1. Compounds belonging to group 2 could not be observed in any of the soils during second sampling (15 days). T test performed to compare group 2, O.O in soil 1 and 2 after 0 and 30 days of incubation gave 0.064 and 0.057 respectively. These values were higher than 0.05, which was set as the level of significance. Therefore, statistics proves that there was a significant increase in compounds forming group 2, O.O in both soils In this case, soil I (pod soil) contains more organic matter and lesser water content as compared to the more clay like soil II. This infers that more oxygen will be available in soil I than soil II. These findings were supported by Atlas (1981): different factors account for changes or loss of some of the components of contaminant in soil, which leads to intermediate products or other end products

27

3.5 Summary Refining process, presence of additives, base component and time of usage are determinants for chemical composition of motor oils. These determinants account for the unstable chemical composition of any motor oil (ATSDR, 1997a). Therefore, oils degrading in soils produce different transformation compounds with varying quantities during the degradation process. FTIR analyses showed that aliphatic, carbonyl, aromatic and ether were the main functional groups present in the studied hydraulic ester oil. Comparison with spectrum of mineral oil showed that presence or absence of these functional groups distinguishes ester oil from mineral oil Based on the physical parameters determined in this study, podsol soil had more organic matter and less water content as compared to clay-rich soil. Therefore, podsol soil most probably contained more microbes and oxygen than the clay-rich soil. Pattern of increment of similar organic compounds, which were not separated by gas chromatograph but eluted as group, were not totally the same in both soils. Though one of the groups was not noticed during second sampling in neither of the soils, the pattern of increment was noticed to be more pronounced in the podsol soil. Thus, the amounts of organic compounds in the contaminated soils changed over time. There was considerable amount of oil remaining in the soil at the end of the study (30 days).

28

Chapter 4

4. Conclusions The results obtained in this study shows that irrespective of the age of ester oil, they all contain the same functional groups, though in different relative amount, if they have the same base constituents: aliphatic, ester, ether and aromatic. However, there is a difference between ester and mineral oil because they differ in base constituents and additive composition. Hydraulic ester oil, like other organic pollutants, does not remain the same in the soil with time, i.e. it is transformed during degradation. Though soil type affect the transformation process due to difference in moisture content and microbial population amidst other factors, transformation of both fresh and old ester oil occurs. The degradation process, which is evidenced by transformation of the initial compound, leads to production of different intermediate, more oxidized, products, over time. These products may not remain the same all through the degradation process; hence different quantity and concentration of specific degradation products could be found in soils at any point in time. 4.1 Recommendation Despite the level of degradation of environmentally friendly oils like ester oil in soils, effective determination of end of degradation process and quantification of the pollutant in the soil at any point in time is still a concern. Therefore, it will be of interest to research into effective determination of end of degradation and intermediate products formed through transformation of compounds during degradation. The extraction process employed in this study could be developed to have more appropriate representation of the extract for both FTIR and chromatograph analysis.This would properly bring about better quantitative and qualitative results.

29

References Agency for toxic substances and disease registry (ATSDR).1997a. Total Petroleum Hydrocarbons, www.atsdr.cdc.gov/toxprofiles/tp123-c-3.pdf (accessed 04/04/2007)

Alonso,S.J., Sastre, L.J.A.,Romero-Avila,C.,and Romero, L.E.J (2005). Combustion of rapeseed oil and diesel oil mixtures for use in the production of heat energy. Fuel processing technology. 87, 97-102.

Anand, O.N., and Chhibber, V.K., (2006). Vegetable oil derivatives: environment-friendly lubricants and fuels. Journal of synthetic lubrication Vol 23, Issue 2, pp. 91- 107

Atlas, R.M., (1981). Microbial degradation of petroleum hydrocarbons: an environmental perspective. Microbial Reviews 45, pp. 180-209

Avinash Kumar, 2007. Agarwal Biofuels (alcohols and biodiesel) applications as fuels for internal combustion engines. Progress in Energy and Combustion Science 33 (2007) 233–271

Dagaut, P., Gai, S., and Sahasrabudhe, M (2007). Rapeseed oil methyl ester oxidation over extended ranges of pressure, temperature, and equivalence ratio: Experimental and modeling kinetic study.Proceedings of the Combustion Institute, Vol 31, Issue:2, Pg.2955-2961

Didem, O., and Filiz, K, (2004). Production and characterization of bio-oil and biochar from rapeseed cake. Renewable Energy, vol 29, Issue 5 pp. 779-787

Douglas, A.S., and Donald, M.W (1982). Fundamentals of Analytical chemistry. 4th Edition.CBS college publishing.

Environmental Protection Agency (2005). Method 8000B Determinative Chromatographic separations (online). Available from: http://www.epa.gov/epaoswer/hazwaste/test/pdfs/ (Accessed 04/06/2007)

Haigh, S.D., (1994). Fate and effects of synthetic lubricants in soil: biodegradation and effect on crops in field studies, The Science of the Total Environment 168 (1995) 71-83

Hansen, L.K., Jakobsen, R., Postma, D., (2001) Methanogenesis in a shallow sandy aquifer, Rømø, Denmark. Geochimica et Cosmochimica Acta 65, 2925–2935

Hewstone, R.K., (994).Health, safety and environmental aspects of used crankcase lubricating oils. The Sciences of the Total Environment 156, pp. 255–268.

Jirasripongpun, K.(2002). The characterization of oil-degrading microorganisms from lubricating oil contaminated (scale) soil, Letters in Applied Microbiology, vol 35, pp. 296–300

Kalligeros, S.. Zannikos, F. Stournas S., Lois E, G. Anastopoulos, Ch. Teas and F. Sakellaropoulos. (2003). An investigation of using biodiesel/marine diesel blends on the performance of a stationary diesel engine. Biomass and bioenergy.vol.24, issue 2.Pg.141-149

Levermore,D.M., M. Josowicz, W. S., Rees, Jr., and J.Janata. 2001. Headspace Analysis of Engine Oil by Gas Chromatography/Mass Spectrometry. Analytical Chemistry. Vol 73. 1361-1364

30

Lovley, D.R., and Anderson, R.T., (2000) Influence of dissimilatory metal reduction on fate of organic and metal contaminants in the subsurface. Hydrogeology Journal 8, 77–88.

Map of Sweden (online). Google. Available from www.lib.utexas.edu/maps/europe/sweden_div96.jpg (accessed 21/04/2007)

Martha M. C., Roberlu A. C., Hermesson J. D., Luiz E. B., Valter J.,and Antonio G. S.(2005). Rheological Behavior of Castor Oil Biodiesel. Energy and fuel. vol 19. 2185-2188

Mc Neill., J. (2000). Something New Under the Sun. An environmental history of the twentieth – century world. Penguin books

Mercurio, P., Burns,K.A., and Negrib, A., (2003). Testing the ecotoxicology of vegetable versus mineral based lubricating oils: 1. Degradation rates using tropical marine microbes, Environmental Pollution 129 (2004) 165–173

Merrain. A, (1989). Double low oilseed rape in France. Factors affecting glucosinolate level. Aspect of Applied Biology. vol 23. pp. 109-116

Morelli, I.S., Del Panno, M.T., De Antoni G.L and Painceira, M.T (2005). Laboratory study on the bioremediation of petrochemical sludge-contaminated soil. International Biodeterioration & Biodegradation vol 55, issue 4, pp. 271-278

Norris,R.D (1994). Handbook of Bioremediation, CRC Press, Boca Raton, FL,

Norton, J.M (2002) "Soil microbiology", in AccessScience@McGraw-Hill, http://www.accessscience.com, DOI 10.1036/1097-8542.632000, last modified: July 15, 2002

Pal, M., and Singhal, S (2006).Environmentally adapted lubricants, Part II. Hyraulic fluids. Journal of synthetic lubrication, vol 17, issue 3, pp: 219-224

Petro-Canada (2007). Petro-Canada. Available from http://www.petro-canada.ca/en/productsandservices/355.aspx (accessed 19/04/2007)

Philip, R., Westlake, D.W.S., Jobson, A., and Cook, F.D., (1974). Biodegradability and crude oil composition, Canadian Journal of Microbiology 20, 915–928.

Pirri, D.M.,and Wessol, A.A., (1998). Lubrication fundamentals (2nd edition). Marcel Dekker inc. New York.

Remmele, E., and Widmann, B. (2006). Suitability and environmental compactibiity of rapeseed oil based hyrauic fluids for agricultural machinery. Journal of synthetic lubrication, Vol 16, Issue 2, pp 129-145

Silke, S.A., Vomberg, A., Schmitz,A.A., FaMbender,U.B., and Klinner U.A., (2001).interaction between bacterial population during degradation of a lubricant base oil. Microbiology Ecology 38, 97 - 104

Sagar, A.D. (1995). Automobiles and global warming: Alternative fuels and other options for Carbon dioxide Emissions Reduction. Environmental Impact Assessment Review, vol 15. pp.241-274

Shane, M.P., Harvey P.M, Stark J.S., Snape I and Riddle, M.J, (2007). Biodegradation of petroleum products in experimental plots in Antarctic marine sediments is location dependent. Marine Bulletin 54, 434-440

31

Smil, V.(2003). Energy at cross roads: global perspectives and uncertainty. Cambridge press

Svensk standard SS-ISO 11465: soil quality- determination of dry matter and water content on a mass basis- gravimetric method

U.S Census Bureau, Population division, international program center. http://www.census.gov/ipc/www/world.html (accessed 07/01/2006)

U.S Environmental Protection Agency (1994). Environmental regulation and technology: managing used motor oil, EPA/625/R-94/010.

Van Gestel, C.A.M., Van der Waarde, J.J., Derksen, J.G.M., Van der Hoek, E.E., Veul, M.F.X.W., Bouwens, S., Rusch, B., Kronenburg, R., Stokman, G.N.M., (2001). The use of acute and chronic bioassays to determine the ecological risk and bioremediation efficiency of oil-polluted soils. Environmental Toxicology and Chemistry 20, 1438–1449.

Vazouez-Duhalt (1989). Environmental impact of used motor oil. Science of the Total Environment 79, 1-23

William,K. (1991). Organic spectroscopy. 3rd edition. Macmillan.

Yukiko, N., Tomoko, N.,Takaashi, N., and Naoki, O(2003). Toxicology, Vol 187, Issues 2-3, pg 205-216

Zhang, C.G., Leung, K.K., Wong, Y.S., Tam, N.F.Y. (2007) Germination, growth and physiological responses of mangrove plant (Bruguiera gymnorrhiza) to lubricating oil pollution. Environmental and Experimental Botany, vol 60, pp. 127–136

Zie,J. (1997). Examination of used motor oils by flame AAS for criminalistic purposes: a diagnostic study. Forensic Science International, vol 91, pp. 171–179

32

Appendices

Appendix 1.Physical properties of the soils

Table 5: % water composition and loss of ignition (organic matter content) of the two soils Soil I (1) Soil I (2) Soil 1

Mean Soil II (1)

Soil II (2)

Soil II Mean

Wt. crucible 28.427 33.885 31.156 30.434 30.913 30.674 Wt crucible + fresh soil (g)

37.125

44.490

40.806

49.001

48.024

48.513

Wt. of fresh soil (g)

8.698 10.605 9.652 18.567 17.111 17.837

Wt of crucible + soil after drying at 105o

C (g)

32.892

38.982

35.937

43.191

43.578

43.385

Wt. of dry soil (g)

4.233 5.558 4.896 5.810 4.446 5.128

Water content (g)

4.465 5.047 4.756 12.757 12.665 12.711

% water content

51.351 47.591 49.471 68.094 74.017 71.056

Wt. of burnt soil + crucible at 550oC (g)

31.320

37.085

34.203

42.319

42.499

42.409

Wt. of burnt soil (g)

1.572 1.897 1.735 0.872 1.079 0.976

% composition of organic matter

37.137

33.321

35.229

18.129

19.677

18.903

33

Appendix 2.Chromatograms of soil and contaminant

-50

100

200

300

400

500

4,0 10,0 15,0 20,0 25,0 30,0 35,0 40,0 45,0

mV

min

April 2007 #4 3 soil 2 rep 2 Int_Chan_2

1 - Hexadecane - 20,206

Figure 10: Chromatogram of soil 2. Hexadecane was added as internal standard.

Figure 11: chromatogram of old ester oil aged by utilized as hydraulic oil for 16000 hours. Hexadecane was added as internal standard

-100

125

250

375

500

625

800

4,0 10,0 15,0 20,0 25,0 30,0 35,0 40,0 45,0

mV

min

April 2007 #22 old est oil Int_Chan_2

1 - 6,228

2 - Group 1 - 16,189

3 - Hexadecane - 20,277

4 - peak 2 - 31,115

5 - Group 2 - 37,612

34

Figure 12: chromatogram of old mineral oil. Hexane was added as internal standard.

-100

125

250

375

500

625

800

4,0 10,0 15,0 20,0 25,0 30,0 35,0 40,0 45,0

mV

min

April 2007 #24 old min oil Int_Chan_2

1 - Group 1 - 16,754

2 - Hexadecane - 20,279

3 - 23,7744 - 24,3145 - 30,284

6 - Group 2 - 37,277

35

Appendix 3. Areas from GC chromatogram

Table 6: Area (mV*min) of Group 1 and 2 in chromatograms obtained from extraction of the two soils withdrawn from the degradation study 0 day 15 days 30 days Group 1, F.O in soil 1 35.449 368.487 486.123 Group 1, F.O in soil 2 38.12 127.66 266.2 Group 2, F.O in soil 1 48.36 8093.937 239.544 Group 2, F.O in soil 2 1157.765 7766.91 256.88 Group 1, O.O in soil 1 58.931 323.634 455.234 Group 1, O.O in soil 2 83.812 158.964 287.223 Group 2, O.O in soil 1 90.111 0 213.547 Group 2, O.O in soil 2 120.451 0 242.284

Table 7: Presence of Group 1 and 2 in the contaminants (soil 1 and 2) at 0, 15 and 30 days respectively Samples Group 1 Group 2 Ave. value Ave. Value Group 1 Group 2 Pure soil 1st sampling (0 day) 1 1 Soil 1 rep 1 0.000 0.000 0 0 2 1 Soil 1 rep 2 0.000 0.000 3 1 Soil 2 rep 1 0.000 0.000 4 1 Soil 2 rep 2 0.000 0.000 0 0 3rd sampling (30 days) 5 3 soil 1 rep 1 0.000 0.000 0 0 6 3 soil 1 rep 2 0.000 0.000 7 3 soil 2 rep 1 0.000 0.000 8 3 soil 2 rep 2 0.000 0.000 0 0 Pure oil 9 1 Fresh ester oil (F.O) rep 1 44.084 4610.409 10 1 Fresh ester oil rep 2 77.697 11051.889 60.891 7831.141 11 1 Old ester oil (O.O) rep 1 96.753 8964.120 12 1 Old ester oil rep 2 122.415 290.674 109.584 4627.397 Oil in soil 1st sampling (0 day) 13 1 soil 1 + F.O 1 27.562 0.000 14 1 soil 1 + F.O 2 49.395 70.066

36

15 1 soil 1 + F.O 3 29.389 26.654 35.449 48.36 16 1 soil 1 + O.O 1 41.680 0.000 17 1 soil 1 + O.O 2 47.378 41.708 18 1 soil 1 + O.O 3 87.736 138.513 58.931 90.111 19 1 soil 2 + F.O 1 66.447 127.606 20 1 soil 2 + F.O 2 31.493 2424.827 21 1 soil 2 + F.O 3 16.419 920.861 38.12 1157.765 22 1 soil 2 + O.O 1 94.057 112.437 23 1 soil 2 + O.O 2 0.000 0.000 24 1 soil 2 + O.O 3 73.645 128.464 83.812 120.451 2nd sampling (15 days) 25 2 soil 1 + F.O 1 344.609 0.000 26 2 soil 1 + F.O 2 374.059 8020.893 27 2 soil 1 + F.O 3 362.915 8166.980 368.487 8093.937 28 2 soil 1 + O.O 1 330.181 0.000 29 2 soil 1 + O.O 2 273.531 0.000 30 2 soil 1 + O.O 3 366.380 0.000 323.634 0 31 2 soil 2 + F.O 1 122.894 7554.296 32 2 soil 2 + F.O 2 107.044 7050.311 33 2 soil 2 + F.O 3 153.042 8696.123 127.66 7766.91 34 2 soil 2 + O.O 1 148.248 0.000 35 2 soil 2 + O.O 2 139.235 0.000 36 2 soil 2 + O.O 3 189.395 0.000 158.964 0 3rd sampling (30 days) 37 3 soil 1 + F.O 1 470.173 215.061 38 3 soil 1+ F.O 2 450.672 244.366 39 3 soil 1+ F.O 3 537.524 259.206 486.123 239.544 40 3 soil 1+ O.O 1 439.857 230.890 41 3 soil 1 + O.O 2 475.381 198.808 42 3 soil 1+ O.O 3 450.463 210.942 455.234 213.547 43 3 soil 2 + F.O 1 283.798 258.794 44 3 soil 2 + F.O 2 240.901 265.188 45 3 soil 2+ F.O 3 273.902 246.657 266.2 256.88 46 3 soil 2 + O.O 1 276.033 240.890 47 3 soil 2 + O.O 2 263.818 217.815 48 3 soil 2 + O.O 3 321.818 268.148 287.223 242.284 Mineral oil 49 1 Fresh mineral oil rep 1 53.031 0.000 50 1 Fresh mineral oil rep 2 66.760 0.000 59.896 0 51 1 Old mineral oil rep 1 53.496 0.000 52 1 Old mineral oil rep 2 45.636 0.000 49.566 0

37

Appendix 4. Spectrum from FTIR analyses

Figure 13: FTIR spectrum of fresh ester oil in soil I after 30 days of incubation

Figure 14: FTIR spectrum of fresh mineral oil

38

Appendix 5. Analysis of old oil from Bodycote